‘Tis the Season…

Red and green are indeed the colors of Christmas, but that’s not the season we’re talking about. The season is summer, and the colors are blue and green – as in blue-green algae blooms impacting the local watershed in the summer season. And it’s nothing to celebrate.

As we’ve seen in the recent past, as temperatures heat up, algae blooms have unfortunately become the new normal, around North America and around the globe.

Primarily caused by nutrient pollution in rivers, lakes and streams, and exacerbated by warmer temperatures, algae blooms close beaches and overwhelm our favorite fishing holes, putting a damper on summer fun. But they do much more than dampen our spirits or put a frown on kids’ faces. Algae blooms upend the ecological balance in local waterways, as they kill aquatic plants and sicken animals, and are harmful to pets and humans alike.

According to the NOAA (National Oceanic and Atmospheric Administration) in the United States, algae are at the bottom of the food chain in all natural environments. And they occur naturally in fresh, marine (salt), and brackish (mixture of fresh and salt) water. For any healthy aquatic ecosystem, algae are an important and critical component. In the natural world, too much of a good thing can be disruptive, harmful, or even deadly to other organisms in that ecosystem. Such is the case when it comes to algae.

Harmful algae blooms

Harmful algae blooms (HABs) occur when too much algae is present and it becomes toxic to the ecosystem within which it exists. HABs in fresh water typically consist of cyanobacteria or commonly referred to as blue-green algae. HABs are becoming more frequent, as reported by the US EPA, and will continue this trend as the impacts of climate change continue to exacerbate the root cause of HABs around the world.

Nutrient pollution?

There are a number of factors that help fuel harmful algae blooms, and increased water temperatures are certainly one of the primary culprits. But nutrient pollution is another key problem that has led to the increased occurrence of algae blooms. Naturally occurring nutrients (primarily nitrogen and phosphorus) at normal, balanced levels in the ocean, lakes, rivers and other bodies of water are healthy, as they support the growth of algae and aquatic plants. These plants in turn provide food and habitat for fish, shellfish, and smaller organisms that live in the water. Too much nitrogen and phosphorus create what is referred to as nutrient pollution.   

Why is nutrient pollution a problem?

Nutrient pollution, created by excessive levels of nitrogen and phosphorus in bodies of water, typically originates from fertilizer or waste runoff from factory farming, and industrial and municipal wastewater treatment plants. These increased levels of nutrients can deteriorate water quality, as algae can grow rapidly, reducing or even eliminating the oxygen supply and reducing the exposure to sunlight. Nutrient pollution has been exacerbated by climate change, with increased water temperatures (more conducive to algae growth) and bigger storms (heavier rainfall leading to increased erosion leading to a greater influx of nutrients from the runoff). Nutrient pollution leads to habitat damage, loss of aquatic life, drinking water contaminated with toxins and bacteria, and ultimately negative impacts on human health. According to the New York State (U.S.) Department of Health, contact with contaminated surface waters can cause diarrhea, nausea, or vomiting; skin, eye, or throat irritation; and allergic reactions or breathing difficulties.

What can be done about it?

The story isn’t all doom and gloom. Nutrient pollution is preventable, and wastewater treatment plants have been identified as a critical part of the solution for implementing technologies aimed at addressing nutrient pollution. And with continued diligence from municipalities, industries, and consumers alike, the tide can be turned and there can be cause for celebration in the summer season – and not just for July 4^th. But HABs will continue to wreak havoc on the ecosystems in our bodies of water, from our biggest oceans to our smallest rivers and streams, unless we take a serious look at the root cause of HABs and begin to make changes, as if our world depends on it.